Multi-plate disc brake and disc spacing means



March 3, 1970 D. DEwAR 'l 3,498,413

MULTI-PLATE DISC BRAKE AND DISC SPAGING MEANS FiledMay 1s. 1968 UnitedStates Patent O 3,498,418 MULTI-PLATE DISC BRAKE AND DISC SPACING MEANSDouglas Dewar, Su'etton-on-Dunsmore, near Rugby, Eugland, assignor toThe Dunlop Company Limited, Birmingham, England, a corporation of GreatBritain Filed May 13, 1968, Ser. No. 728,590 Claims priority,application Great Britain, May 18, 1967, 23,114/ 67 Int. Cl. F16d 55/40U.S. Cl. 188-72 2 Claims ABSTRACT OF THE DISCLOSURE A disc brake of themulti-plate type having rotor discs formed from separate ring segments,annular spacing members being arranged around the torque tube betweenthe torque tube and the rotor discs.

This invention relates to disc brakes of the multi-plate kind comprisinga plurality of annular friction discs arranged coaxially, alternatediscs being keyed respectively to a rotatable member and a nonrotatablemember and means being provided for compressing the discs togetheraxially to produce frictional engagement between the discs. One kind ofmulti-plate brake incorporates friction discs formed from a plurality ofseparate ring segments, each segment being held in assembly with theother segments by disconnectible interlocking means which link togetherthe adjacent end portions of the successive segments in such a mannerthat they are able to move axially relative to one another. Such a brakeis described in the specication of our U.S. Patent No. 3,105,575.

One object of the present invention is to provide means for limiting thedistortion in a direction radially inwardly of brake discs of the kinddescribed above.

According to the invention, a disc brake of the kind described comprisesa plurality of annular rotor brake discs arranged to be keyed at theirouter peripheries to a wheel so as to be rotatable thereby, the rotordiscs being interleaved coaxially with stator discs mounted on andnonrotatably keyed to a nonrotatable torque tube, each rotor disc beingformed from a plurality of separate ring segments, each segment beingheld in assembly with the other segments by disconnectible interlockingmeans which link together the adjacent end portions of the successivesegments in such a manner that they are able to move axially relative toone another, the rotor discs being tted loosely around the torque tubeand spacing members being provided one for each rotor disc, each spacingmember comprising an annular member being a loose fit axially betweenadjacent stator discs in all states of wear of the stator and rotordiscs and being a loose fit radially between the torque tube and therotor disc.

The spacing members may take the form of cylindrical steel tubes thelengths of which are shorter than the axial length of the rotorsegments.

One embodiment of the invention will now be described, by way of examplewith reference to the accompanying drawing which shows an axialcross-sectional View of part of a wheel incorporating a disc brakeaccording to the invention.

A multi-plate disc brake for an aircraft wheel is described andillustrated in the specication of British Patent No. 931,031. In thisbrake a plurality of interleaved 3,498,418 Patented Mar. 3, 1970 rotor 1and stator 2 discs are mounted coaxially on a torque tube 3 formedintegrally at one end 4 With a torque member 5 secured to a nonrotatableaxle 6 of the aircraft. The torque member 5 houses a number of hydrauliccylinders 7 and pistons 8 arranged to press the discs axially towards areaction member 9 secured at the other end 10 of the torque tube 3. Therotor discs 1 are provided with driving dogs 11 on their outerperipheries for engagement with corresponding axial keyways 12 formed inthe rim 13 of an associated wheel V14, while the stator discs 2 aresplined at their inner peripheries 15 to the torque tube 3.

The rotor discs 1 are each made up from eight identical annular steelsegments which each have an extension at one end with a rounded head anda recess at the other end to receive the head of the extension formed onan adjacent segment, the segments being linked together in this mannerto form an annular disc. This rotor construction is described andillustrated in detail in the specication of British Patent No. 931,031.The stator discs 2 are of similar construction except that they areprovided on each side with sintered-on friction pads 16 for engagementwith the rotors 1.

The dimensions of the rotor discs 1 are such that they t loosely aroundthe torque tube 3, Spacing members in the form of cylindrical steeltubes 17 the lengths of which are shorter than the axial lengths of therotor discs 1 are tted loosely within the inner peripheries of the rotordiscs 1 and are arranged also to iit loosely around the torque tube 3.

It has been found that as a result of thermal shock during service thesegments of the rotor brake discs in a brake of the kind described abovemay be distorted and caused to project radially inwardly to such anextent that they foul the torque tube. The interposition of steel tubesas described above effectively prevents fouling from taking place andensures satisfactory operation of the brake. Although the presentinvention has been illustrated and described in connection with a singleexample embodiment, it will be understood that this is illustrative ofthe invention and is by no means restrictive thereof. It is reasonablyto be expected that those skilled in this art can make numerousrevisions and adaptations of the invention and it is intended that suchrevisions and adaptations will be included within the scope of theinvention,

Having now described my invention, what I claim is:

1. A disc brake comprising a plurality of annular rotor brake discshaving keys at their outer peripheries forming drivable connections witha wheel so as to be rotatable thereby, a plurality of stator discsinterleafed coaxially with said rotor discs and having keys formingnonrotatable connections which provide for axial slidable movement, anonrotatable torque tube providing a mounting for said stator discs,each rotor disc being formed from a plurality of separate ring segments,each such segment including disconnectable interlocking means which linktogether the adjacent end portions of successive segments in such mannerthat each is moveable axially relatively to the adjoining ring segment,said rotor disc being tted loosely around said torque tube, andcylindrical spacing members provided one for each rotor disc andproportioned to be disposed radially between a respective one of saidrotor discs and said torque tube to be engageable by the radially innerperiphery of a respective one of said rotor discs, each spacing memberbeing propor- References Cited tioned to be of less axial dimension thanthe axial dimen- UNITED STATES PATENTS sion of the rotor disc to providea loose t between adjacent stator discs in all states of wear of thestator and 795207 7/1905 Eastwood 2,217,357 10/1940 Coe 192-70-28 rotordlscs and thereby unengageable by sa1d stator discs 5 3 105 575 10/1963D ar t al 188 218 during a brake application to preclude axialdistortion of 3171522 3/1965 Plie e al '88 2 1"6 X said spacing members,to maintain a substantially loose it radially between said torque tubeand the associated GEORGE E A HALVOSA, Primary Examiner rotor disc.

2. A disc brake according to claim 1 wherein the cylin- 10 U.S. Cl. X.R.drical spacing members are of steel composition. 19270.11

